Insulating window



May 3, 1960 H. BLASZKOWSKI INSULATING WINDOW 2 Sheets-Sheet 1 Filed June 16. 1958 QV/A l I; INVENTOR. 4.4 /4 BMszKousK/ May 3, 1960 H. BLASZKOWSKI INSULATING WINDOW 2 Sheets-Sheet 2 Filed June 16, 1958 INVENTOR. BM $ZK WSK I m-rom/sf 1 29 Mar United States PatentO 2,934,801 INSULATING wnsnow Henry Blaszkowski, Dearborn, Mich. Application June 16, 1958, Serial No. 742,421

8 Claims. c1. 20-565) This invention relates to improvements in insulating windows, that is, to windows containing two or more panes of glass, with a stagnant air space therebetween providing insulation against heat and noise, and sealed off from the ambient air so as to prevent the entry of moisture and dirt. More particularly it relates to improved methods and means of mounting multipane insulating windows, in order to provide a hermetical seal for the stagnant air space between panes, despite expansions and contractions caused by changes in temperature and pressure.

This application for patent constitutes a continuationin-part of my co-pending application Serial No. 677,290, filed August 9, 1957.

The use of double panes of glass, and even triple panes of glass, in order to provide insulation against heat and noise is well known. Such windows comprise two or more parallel panes of glass, usually mounted in a resilient material such as rubber. That is to say, there is rubber between the panes at their edges, rubber on the outside of said edges, and rubber below said edges. Means for compressing the rubber so as to seal the glass panes therein, and to prevent air from leaking into or out of the air space between panes may also be provided.

In principle, the idea is extremely simple. However, in order to be effective as an insulating device, it is neces sary that the stagnant air space between the panes of glass really be stagnant; that is to say, that the seal be really tight. Not only is the insulating value of these windows dependent on the maintenance of a tight seal but, in addition, visibility also depends on it. For if moisture condenses on the inner surfaces of the glass, or if a film of grease and dirt accumulates thereon, visibility will obviously be adversely affected, if not altogether destroyed. And since it is often impracticable to clean these surfaces, it is clear that a really tight seal is vital.

I am aware that a number of attempts have been made from time to time, to provide a satisfactory solution to the problem. These have in general involved the use of rubber sealing strips as gaskets, with various means for compressing said gaskets against the panes. Experience, however, shows that such methods of this type as are presently known cannot provide a sufficiently strong uniform pressure to make a really air-tight seal.

In the case of a relatively loose storm window of the conventional type, some reduction in heat loss is achieved. There is no significant problem of condensation of moisture in such case, because there is so much circulation be: tween the ambient air and the space between panes that no significant difference in humidity can exist for very long. However, the dirt problem is very severe, because the entry of such large volumes of air causes the rapid deposition of a film of grease and dirt on the inner surfaces of the panes. At the end of a year or so, cleaning becomes imperative. If this is a physical impossibility, or substantially soas in many applications (e.g. in office buildings, or in non-slidable picture.Windows)-- yzthe results are extremely unsatisfacto y.- ,In such cases in fact, conventional storm windows really cannot be used; multi-pane insulating windows are required.

The use of a conventional rubber sealing strip in the normal way (i.e. without special elforts to achieve uniform compression), substantially reduces the circulation between ambient air and the space between panes. One

result is thus that the insulating effectiveness may reach. a reasonably good level. Another is that dirt may take between ambient air and the space between panes is slow,

the window may remain fogged for very substantial periods of time. Thus, in order to decrease the dirt problem, one finds that one has introduced a condensation problem. All in all, therefore, one has not achieved a solution to the problem of maintaining good visibility conditions. One has a pretty good insulator; but it is not a pretty good window.

The next step in the evolution of insulating windows has been the introduction of factory-sealed windows. These are the first true insulating windows. The space between panes is truly stagnant. The insulating quality is high. And there is no dirt or condensation problem, insofar as the stagnant space is concerned. The difficulties with these windows are the extremely high first cost, high insurance cost, and expense and difliculty of repair and replacement. The fact that factory-fabricated insulat ing windows can be bought only in certain specific standard sizes also places limitations in design, especially where curved windows are involved.

The fact that such expensive solutions have nevertheless found very substantial commercial success clearly indicates that the problem itselfi.e. obtaining good insulating quality without visibility impairmentis a pressing problem, a problem of great commercial importance, and one for which no obvious answer exists.

Thus, there remains the problem of providing aseal as good as that presently possible only with factory-fabricated insulating windows, which is at the same time in expensive, readily adapted to any size or shape of window including curved windows, and which can be installed and repaired at the job site instead of requiring factory fabrication.

. Of course, air-tight seals are well known in technology, but the problem in connection with insulating windows is to obtain a sealwhich is not only'etfective, but also extremely simple in design and installation, and extremely low in cost. Complicated constructions may make excellent air-tight seals for scientific and industrial apparatus, but have no place in the construction of buildings, or in vehicles such as autos, trains, buses, and planes,

' .where simplicity is required.

with seasonal changes, and by pressure variations with changes in elevation in the case of vehicles, must be accounted for without causing breakage on the onehand, or air leakage 0n the other.

This is the problem I have attacked, and thisis the problemwhich my invention solves. i

' edges or periphery 3 Objects An object of my invention is thus to provide a multipane insulating window with a truly stagnant space between panes.

bled on the job.

A third object is to provide such a multi-pane insulating window which is extremely simple in design and installation.

A fourth object is to provide such a multi-pane insulating window which is low in first cost, low in shipping cost, low in insurance cost, and low in the cost of main tenance and repair.

A fifth object is to provide a multi-pane insulating window with a seal which is under sufficiently high and sulficiently uniform pressure to make it substantially air-tight, and to remain so despite variations in atmospheric temperature and pressure.

A sixth object is to provide a multi-pane insulating window with a seal which is rendered substantially air-tight by pressure exerted by an inflated tubular member or members.

A seventh object is to provide a method for tightly sealing the air-space or air-spaces between the panes of a multi-pane insulating window.

An eighth object is to provide a method for tightly sealing the air-space or air-spaces between the panes of a multi-pane insulating window by inflation of a flexible tubular element.

A ninth object is to provide a uniformly high pressure between the panes of a multi-pane insulating window and a gasket, or a resilient sealing strip circumscribing the thereof and acting as a gasket therefor, by inflation of a flexible tubular member which is so placed as to cause said panes and gasket or sealing strip to be compressed tightly against each other.

A tenth object is to provide a uniformly high pressure between the panes of a multi-pane insulating window and a gasket, or a resilient sealing strip circumscribing the edges or periphery thereof and acting as a gasket therefor, by inflation of a flexible tubular member which is so placed as to cause said panes and gasket or sealing strip to be compressed against each other, said flexible tubular member being restrained from attaining a circular crosssection.

Advantages prevents the subsequent entry of moisture-laden air between the panes of the insulating window with consequent condensation and loss of visibility therethrough.

A third advantage is that the tight air seal provided keeps the inner surfaces of the glass panes of an insulating window clean.

A fourth advantage is that no large expensive fabricat ing equipment is required, thus reducing the initial cost, the cost of repairs and replacements, and the cost of insurance.

A fifth advantage is that the insulating window can be shipped disassembled, thus greatly reducing shipping costs.

A sixth advantage is that there are no limitations on the design of my insulating windows as regards size, shape, or curvature.

Other objects and advantages will more fully appear in connection with the following description and drawings, wherein are disclosed preferred embodiments of the invention.

Drawings Fig. 1 is a fragmentary perspective view of a partial as-i sembly of a first embodiment of my invention.

Fig. 2 shows a fragmentary sectional view of the assembled insulating window, utilizing the partial assembly shown in 'Fig. l as a component part.

!Fig. 3 is a fragmentary sectional view of a second embodiment which also utilizes the partial assembly shown in Fig. 1 as a component part.

Fig. 4 is a fragmentary sectional view of a third embodiment of the invention.

'Fig. 5 is a fragmentary sectional view of a fourth embodiment of the invention.

Fig. 6 is a fragmentary sectional ment of the invention.

Fig. 7 is a fragmentary sectional view of a sixth embodiment of the invention.

Fig. 8 is a fragmentary sectional view of a seventh embodiment of the invention.

Fig. 9 is a fragmentary sectional view of an eighth embodiment of the invention.

:Fig. 10 is a fragmentary sectional view of a ninth embodiment of the invention; and

Fig. 11 is a fragmentary sectional view of a tenth emview of a fifth embodibodiment of the invention.

Similar numerals refer to similar parts in each of the drawings.

Description scribes the edges or the periphery of the glass panes 10 and 11.

The partial assembly A shown in Fig. l is by no means novel, but is substantially the basis of most of the insulating windows which have hitherto been proposed, other thanthe factory-fabricated type. Obviously, an air-space 16 will be enclosed between the panes 10 and 11, but said air-space will not be a really stagnant air-space, because there cannot possibly be an absolutely tight seal between the glass panes 10 and 11 and the resilient sealing strip 13. Irregularities in either glass pane and/ or in the sealing strip will prevent this, and the natural resiliency of the sealing strip 13 is insufficient to overcome such irregularities completely. Thus, any attempt to use a sealing method of this or a similar type can succeed only if some additional means are provided for uniformly compressing said sealing strip 13 against said glass panes 10 and 11, with sufficient uniformly distributed pressure to effectuate a tight seal.

While numerous attempts have hitherto been made to provide such means, they have all been ineffective to accomplish the desired objective, either because insufiicient force was supplied, or because it was not uniformly applied, or both-usually both. If the force is not uniformly distributed, even the maximum force which can be applied without breaking the glass will not be sufiicient to achieve a tight air seal. Furthermore, even aside from this, no means have hitherto been found to apply sufficient force even where it is reasonably well distributed, except by the use of factory fabrication methods.

I have now found a means for supplying pressure in a completely uniform manner, and at the same time supplying as much pressure as is desired or needed to effectuate a tight seal. As shown in Figs. 2-9, the means for applying this pressure is by inflation of a flexible plastic or elastic tube 17.

Thus, in Fig. '2 I have shown an embodiment of my invention, in which the partial assembly A is utilized. Said partial assembly A, comprising panes 10 and 11 mounted in sealing strip 13, is associated with a window sash 18. Said-sash 18 is provided with an upstanding flange 1 9, with the deflated tube 17 also side of the assembly. The assembly A are retained in position by means of a channel-shaped retainer 22, which bears against the platform 20 adapted to enter the groove 21. A gasket 24 may, vided to fill the gap between the top A and the pane 10, in order to keepdirt out.

complete assembly shown in Fig. 2 is made, the tube 17 nel-shaped retainer 22 retains tube 17 in position, f itself retained in position by insertion of tongue provided to keep dirt out of the space between n inflation of the tubes 17 seal is obtained.

i it is not needed in these cases as a crease the total surface of the it so as to increase the 3 In my invention, 'ftheJtype thus shown. However, because of the highly 'eifective results achieved in my invention by the use of one ormore inflatable tubes 17, it is not in general necessaryfor me to use a complete sealing strip 13, such as shown in Figs. 1-3.

indicated below, I may various portions of the sealing strip 13.

Thus, as shown in Fig. 4, I may eliminate the inner -gasket portion 12 between panes 10 and 11, by substituting the inflatable tube 17 therefor.

the inflatable tube 17 itself may act flange 19 at one side, and a substantially flat platform '20 :with a longitudinal "of the platform 20 groove 21 therein, close to the end opposite said flange 19. Said partial assembly A is placed on said platform 20, abutting against on the opposite and the tube 17 if desired, be proof the retainer 22 After the inflated, providing uniform pressure which presses the panes 10 and 11 and sealing strip 13 together to form an airtight seal. a Fig. 3 shows a second embodiment of the invention, in which two inflatable tubes sembly A, comprising panes -13,'is placed on platform 20 17, 17' are utilized. The as- 10 and 11 and sealing strip of sash 18. The flange 22 Chanand is 23 in may be retainer 22 and pane- 10, and flange 22 and pane 11, respectively. and 17', ,an especially tight is in this case channel-shaped to retain tube 17'.

groove 21 of the sash 18'; Gaskets 24 and 24' In the embodiments shown in Figs. 1, 2 and 3, the sealing strip 13 must extend uninterruptedly around the entire periphery of thewindow,

in order to seal off the space '16 between panes 10 and 11 from the ambient atmosphere. 'However, while the inflatable tube 17 must extend around the major portion of the periphery of the window, inorder to provide substantially uniform compression, it is not necessary that it be uninterrupted, since gasket. If desired, it

- may comprise several sections, with substantial gaps (e.g. therebetween, for example at the corners. If this is done, care should be taken to inflate each section of the tube substantially simultaneously, and to roughly the same pressure, in order to distribute the stresses uniformly over the panes.

The term uninterrupted, as used in the present appli- 1 cation for patent, means either that the gasket or equivalent .is a single piece, or else that several pieces have i been joined together (for example, by vulcanizing), with i no substantial gaps therebetween.

In each ofFigs. l, 2, and 3, a complete sealing strip 13 has been shown-comprising a number of portionsinner gasket portion 12 between panes and 11, a pair of outer cushion portions 12 and 12", and a bottom .-cushion portion 12". In the prior art, each of these portions of the sealing strip have been used in order to inglass in contact therewith, possibility of obtaining a tight seal. Imay use a complete sealing strip 13 of Under various circumstances, as dispense with one or more of the In this embodiment, as a gasket, provided it extends, uninterruptedly (at least insofar as its external tion, in which assembly A has been modified 'so as to sealing strip Y stead, the inflatable tube 17 is again obtained, providing a stagnant air space 16.

Fig. 5 shows a fourth embodiment of my invention in which a subassembly B similar to that shown in Fig. 4, is used, said sub-assembly comprising two panes of glass 10 and 11v which have been mounted in a modified sealing strip 13' with tube 17 between said panes 10 and 11. Sub-assembly B is now associated with a window sash 18". Said sash 18" is provided with an upstanding flange 19" at one side, and a substantially flat platform 20" with a longitudinal groove 21" therein, close to the end of the platform 20 opposite said flange 19". Said partial assembly B is placed on said platform 20", abutting against flange 19". The assembly B is retained in position by? means of a retaining member 22", which has a substantiallyflat inner surface 26 which bears against the side of the sealing strip 13', which may also bear against the platform 20 as shown, and which is securely retained in position by means of a longitudinal tongue 23" adapted to enter the groove 21". After the complete assembly shown in Fig. 5 is made, the tube 17 is inflated, providing a tight seal, with a stagnant air space 16.

While sub-assembly A and sub-assembly B do not in themselves provide airtight seals, they may advantageously beshipped as units, in order to eliminate the necessity of cleaning the insides of panes 10 and 11 before final assembly. However I may, if desired, ship the inspace 16 between dividual component assembled.

In Fig. 6, I show an embodiment of my invention in which I have eliminated one of the outer cushion portions 12', and also, the bottom cushion portion 12". The inflatible tube 17 now bears directly against the outer surface of pane 10, itself distributing the force evenly over the outer surface of pane 10. Outer cushion portion 12" is retained in the drawing. Since the bottom cushion portion 12" has been eliminated in the present embodiment, the sealing strip now comprises two separate portions, outer cushion 12" and gasket 12. In this case, gasket 12 must extend uninterruptedly around the periphery of the window, in order to seal off the stagnant panes from the ambient atmosphere. It is not necessary that the outer cushion 12" extend uninterruptedly around the entire periphery of the window, since it is not used as a seal, but merely to distribute the force between pane 11 and upstanding flange 19", in the event that the pane 11 is not quite flat. It is preferred to use an outer cushion portion 12" having substantial resiliency, for this reason. Since it need not be air-tight, I may for example use tape or fabric for this purpose; however I prefer to use a pliable material such as rubber for this purpose, because of its high flexibility and resiliency. As shown in Fig. 6, the gasket 12 may if desired contain a bulbous projection 27 adapted to extend into and be retained by a corresponding concavity in the platform 20", in order to maintain said gasket 12 in position during assembly. (After inflation of tube 17, the gasket 12 will be maintained in position by the frictional force between its surfaces and those of panes 10 and 11.) Alternatively, I may omit said bulbous portion, and hold gasket 12 in place during parts to the job site completely disassembly by other means, such as for example, the use of an adhesive. Similar bulbous projections 27' and 27 which is similar to the expand.

- '12'a and 12"11, each of which 7 may if desired also be provided for outer cushion .12" and inflatable tube 17,. respectively, as shown.

'Fig. 6 also shows a flat typeof retainer 22" similar to that shown in Fig. 5. of said retainer 22" abuts the inflatable tube .17, instead" In this case, the flat surface 26' of the outer cushion portion 12 of the sealing strip 13. This type of retainer 22" may be used in this manner if the inflatable tube 17" is plastic rather thansubstantially elastic; for if it were substantially elastic, it would require vertical restraint, such as is provided dor example by the channel-shaped retainer 22 shown in Fig. 2.

Also shown in Fig. 6 is a vent passage 28 extending through gasket 12 and the platform 20" of sash 1-8. The purpose of said vent passage 28 is to permit of regulation of the pressure in space 16, inorder to prevent the creation of an excessive diflferential pressure across the panes and 11, .i.e. between the space 16 and the ambient atmosphere. Such excessive differential pressures might otherwise be created by substantial compression of the gasket 12 when the inflatable tube 17 is vinflated, and/ or by excessive changes in temperature and/ or pressure, particularly in the case of moving vehicles such as airplanes. In the former case, the vent passage 28 may, for example, be left open to the ambient atmosphere while the inflatable tube 17 is being inflated. In the latter case, it may be connected to a suitable source of compressed air or of vacuum, to establish the desired pressure in space 16. During actual use of the insulating window, vent 28 will of course be sealed up, by any convenient means. It is also to be understood that I may if desired use one or more vents 28 in any of the other embodiments disclosed in the present specification.

Fig. 7 shows another embodiment, which is similar to that shown in Fig. 6, except that the second-outer cushion 12" has also been replaced by a second inflatable tube 17'.

Fig. 8 shows another embodiment, which is also similar to that shown in Fig. 6, except that a hook-shaped retainer 22 has been substituted for the flat retainer 22". This type of retainer, 22"", is preferred for example when the inflatable tube 17 has some substantial tendency to It also tends to keep out dirt, and provides a streamlined appearance.

Fig. 9 shows another embodiment, which is similar to that shown in Fig. 7, with the following modifications: three panes 10, 10a, and 11 are used; the retainer 22" and upstanding flange 19" are each hook-shaped; there are now two vents, 28 and 28a for the respective spaces between panes, 16 and 16a; and bulbous projections have been omitted from the inflatable tubes 17, 17, and the gaskets 12 and 12a, other known means of temporarily maintaining these in position, such as the use of adhesives, being used instead.

If desired, I may utilize three or more panes in constructions similar to each of the embodiments described. For each additional pane added, I add either an additional gasket section between it and the adjacent pane, or an inflatable tube whichacts as a gasket.

Fig. 10 shows another modification of the original sub-assembly A, in which the bottom cushion portion 12 contains a vertical slot 29 in apo'sitionintermediate the grooves in which panes 10 and 11 rest. The .purpose of this slot 2? is to reduce the resistance to compression offered by the bottom cushion 12", especially at the bottom of the window where this material is already under significant compression due to the weight of the panes lit and 11.

Similarly, Fig. 11 shows a further modification of assembly A, above that shown in Fig. 10, wherein the gasket 12 has been separated from the sealing strip, thus forming three separate portions: a gasket 12, and cushions acts as both an outer and a bottom cushion, with a gap 29 therebetween.

While I prefer to construct the sashes 18, '18, and 18", and the retaining members 22, 22", 22", and 22" of a lightweight material such as aluminum, any other of pressure in the inflatable tubes degree of flexibility and material having sufficient strength and rigidity to withstand the amount of stress generated by the application 17 and 17 maybe used.

The material of construction of the sealing strip 13 or '13 may be any material having a substantial but limited compressibility. Some flexibility and compressibility is needed in order to permit uniform distribution of pressure between the panes of glass 10 and 11 and the gasket 12 or sealing strip 13 or 13; but if the compressibility is excessive the change in volume of air in the air-space 16 upon inflation of tube 17 and 17 will cause an excess differential pressure to exist between the air-space and the ambient air, which may result in breaking the glass panes 10, 11. I therefore prefer to use, as the material of construction for the gasket 12 or sealing strip 13 or 13' a rubber or plastic material of limited compressibility. Alternatively, I may relieve excessive pressure from the stagnant air space 16 or 16a by means of a vent passage 28 or 28a, such as shown in Figs. 6-9.

The panes 10 and 11 will normally be glass, but obviously may if desired consist of 'a transparent plastic material, or of a non-transparent material. They may be flat or curved, rectangular or rounded.

The inflatable tubes 17 or 17 are preferably constructed of rubber or plastic. It is not necessary that the tubes be elastic, since pressure may be exerted .by inflating a plastic tube which is constrained by its surroundings to a noncircular cross-section. Since the inflation of a plastic or elastic tube causes it to tend towards a circular cross-section, restraints preventing this cause the tube to exert very substantial pressures against the surroundings through the walls which are thus restrained. The tubes 17 or 17 are preferably initially, non-circular in cross-section, since it is diflicult to squeeze circular tubes into non-circular shapes if their walls are thick enough to withstand pressures of a few atmospheres. They may be oval'in cross-section, or fairly flat or ribbonlike in shape.

Inflation of the tube 17 or 17' may be accomplished in any of a variety of ways. Thus, I may apply fluid pressure to the tube 17 or 17 by'means of a pump, by permitting evaporation of a cooled and/or compressed liquid in said tubes, by the liberation of gases by means of a chemical reaction, by the formation of a rubber latex foam or plastic foam, by filling under pressure with a material which sets by hydration or hydrolysis, or by any other suitable means.

In order to remove any in'tial moisture from the airspace 16 or 16 between panes, I may add asrnall amount of a dehydrating agent therebetween such as, for example, a strip of activated alumina. 1

If desired, I may modify the design of the gaskets .24. and 24' in such a way as to'serve an additional function beyond that described above. By making the gasket sufficiently large, it can constitute a tight air-sealing gasket, in the event that the inflatable tube 17 or 17' should become deflated. The gasket 24 or 24, in this case, is slightly wider than the space alotted .for it, so that it can be inserted therein only when the tube 17 or 17 :isinflated. It may also, if desired, be somewhat wedgeshaped so that it can be forced into its space only partially. In the event of subsequent deflation of tube 17 or 17, the sealing strip 13 will expand, causing the pane 10' or 11 to press the gasket 24 or 24 against the retainer 22 or flange 22, thus maintaining the 'tightair seal between panes 10and 11 and member 13.

While I have described preferred embodiments of my invention, it is to be understood that various modifications in the details of constructionzmay bemade without departing from the spirit of the inventionas defined in the following claims which are directed 'to the-principal features of the invention rather than totthe readily changeable details of construction. .For example, -if one is not concerned with visibility, or with the transmission of light, one may employ non-transparent panes or panels; in this case, one may have an insulating wall or partition. Similarly, one may utilize the same type of structure in an insulating door. For the purposes of this specification, and the claims which follow, the words insulating window are to be understood to include such embodiments of my invention.

I claim:

1. An insulating window comprising: a multiplicity of substantially parallel, spaced apart panes; resilient gasket means positioned between each pair of adjacent panes and circumscribing the periphery of said window; a flexible inflatable tube positioned substantially parallel to said gasket means and circumscribing the periphery of said window; a pair of rigid restraining members positioned externally of said gasket means and said inflatable tube, substantially parallel to said gasket means and circumscribing the periphery of said window, at opposite sides of said window a distance apart so limited as to confine said inflatable tube to a non-circular cross-section; the hydraulic pressure in said inflatable tube being in excess of ambient pressure sufficiently to create and maintain mutual pressure among said panes and gasket means therebetween sufliciently to create and maintain a stagnant insulating space between each pair of adjacent panes.

2. The insulating window set forth in claim 1, wherein the flexibility of said resilient gasket means is limited to such an extent that, upon creating and maintaining mutual pressure among said panes and gasket means sufl'iciently to create a stagnant insulating space between panes, the resulting diflerential pressure between the inner insulating space and the ambient atmosphere will be insufiicient to exceed the strength of said panes.

3. The insulating window set forth in claim 1, also provided with means for temporarily venting the space between each pair of adjacent panesfor the purpose of bringing the pressure between said panes to a predetermined value, and with means for thereafter sealing said venting means.

4. The insulating window set forth in claim 1, also provided with dehumidification means for dehumidifying the air initially present between adjacent panes at the time of sealing, thereby creating a dehumidified stagnant space between panes which is maintained indefinitely in such condition without the necessity of subsequent dehumidification.

5. The insulating window set forth in claim 1, wherein said inflatable tube is positioned externally of said panes.

6. An insulating window comprising: a multiplicity of substantially parallel, spaced apart panes; a resilient sealing strip circumscribing the periphery of said window, and comprising a pair of upstanding outer cushion members positioned externally of and in bearing contact with the outer faces of the outermost pair of panes adjacent peripheries thereof, and a transverse cushion member interconnecting said outer cushion members; a flexible inflatable tube positioned between at least one pair of adjacent panes adjacent the peripheries thereof and substantially circumscribing the periphery of said window; resilient gasket means positioned between each pair of adjacent panes other than those provided with inflatable tubes therebetween, and circumscribing the periphery of said window; a pair of rigid restraining members positioned externally of said sealing strip, substantially parallel thereto, and circumscribing the periphery of said window, at opposite sides of said sealing strip a distance apart so limited as to confine said inflatable tube to a non-circular cross-section; the hydraulic pressure in said inflatable tube being in excess of ambient pressure sufliciently to create and maintain mutual pressure among said panes, sealing strip and gasket means, sufficiently to create and maintain a stagnant insulating space between each pair of adjacent panes.

7. An insulating window comprising: a retaining frame; a multiplicity of substantially parallel, spaced apart panes mounted therein; a resilient gasket positioned solely between each pair of adjacent panes adjacent their peripheries and circumscribing the periphery of said window; an upstanding outer cushion member positioned with the outer face of one of the outermost panes, adjacent the periphery thereof, and circumscribing the periphery of said window; a flexible inflatable tube positioned in bearing contact with the outer face of the other of the outermost panes, adjacent the periphery thereof, and circumscribing the periphery of said window; a pair of upstanding rigid restraining members rigidly afiixed to said retaining frame, positioned externally of and in bearing contact with said outer cushion member and said inflatable tube, and circumscribing the periphery of said window, the distance therebetween being so limited as to confine said inflatable tube to a non-circular crosssection, at least one of said restraining members being removably mounted in said retaining frame; the hydraulic pressure in said inflatable tube being in excess of ambient pressure sufliciently to create and maintain mutual pressure among said panes and gaskets, sufficiently to create and maintain a stagnant space between each pair of adjacent panes.

8. The insulating window set forth in claim 7, wherein said outer cushion member comprises a second flexible inflatable tube similar to the first.

References Cited in the file of this patent UNITED STATES PATENTS 520,226 Weyhe May 22, 1894 647,379 Davis Apr. 10, 1900 1,800,008 Cronmiller et a1. Apr. 7, 1931 1,965,279 Clark July 3, 1934 2,172,091 Scott Sept. 5, 1939 2,430,873 Haas Nov. 18, 1947 2,700,196 Panhard Jan. 25, 1955 2,762,475 Bowden Sept. 11, 1956 2,763,038 Hagerty et al. Sept. 18, 1956 FOREIGN PATENTS 512,255 Great Britain Aug. 31, 1939 685,222 Germany Dec. 14, 1939 

